How many mAh are in one ampere-hour?

Exactly 1000 mAh. The milli- prefix means one-thousandth, so 1 Ah = 1000 mAh. For example, a 3 Ah battery holds 3000 mAh.

Why do some batteries show Ah and others show mAh?

Convention differs by application. Large batteries (car, EV, industrial) use Ah because the numbers stay manageable (e.g. 100 Ah). Small batteries (smartphones, earbuds, power banks) use mAh to avoid decimals (e.g. 5000 mAh instead of 5 Ah). Both units describe the same physical quantity.

Does converting Ah to mAh change the battery's actual energy?

No. Ah and mAh are just different scales for the same charge quantity. A 2 Ah battery and a 2000 mAh battery hold identical charge. Converting the unit does not affect the energy stored.

Can I convert mAh back to Ah with this tool?

Yes. Click the "Swap direction" button to switch from mAh-to-Ah mode. The tool divides your mAh value by 1000. For example, 4500 mAh ÷ 1000 = 4.5 Ah.

How does Ah relate to battery run time?

Run time (hours) ≈ battery capacity (Ah) ÷ device current draw (A). A 10 Ah battery powering a 2 A device lasts about 5 hours. Converting to mAh first: 10000 mAh ÷ 2000 mA = 5 hours — same result.

Ampere Hours to mAh Converter

Name: Ampere Hours to mAh Converter
Availability: InStock
Author: Nham Vu

Enter a battery capacity in ampere-hours (Ah) and instantly get milliampere-hours (mAh). 1 Ah = 1000 mAh.

Battery Capacity Conversion

Value in Ampere-hours (Ah)

Result in Milliampere-hours (mAh)

Formula

mAh = Ah × 1000

1 Ah = 1000 mAh (exact, by definition)

Quick Reference

Ah	mAh
0.5 Ah	500 mAh
1 Ah	1,000 mAh
2 Ah	2,000 mAh
3.5 Ah	3,500 mAh
5 Ah	5,000 mAh
10 Ah	10,000 mAh
50 Ah	50,000 mAh
100 Ah	100,000 mAh

Summary

Enter a battery capacity in ampere-hours (Ah) and instantly get milliampere-hours (mAh). 1 Ah = 1000 mAh.

How it works

Enter your battery capacity value in ampere-hours (Ah) in the input field.
The converter multiplies your value by 1000 (since 1 Ah = 1000 mAh).
The equivalent milliampere-hour (mAh) result appears instantly.
Use the swap button to reverse the conversion from mAh back to Ah.
Copy the result to clipboard with one click.
Enter any decimal value — the conversion handles fractional Ah precisely.

Use cases

Compare battery specs between devices that list capacity in Ah vs mAh.
Convert laptop or EV battery ratings from Ah to mAh for standardized comparisons.
Calculate smartphone battery capacity when the spec sheet uses Ah instead of mAh.
Verify power bank capacity labels that mix Ah and mAh units.
Check whether a replacement battery matches the original mAh rating.
Convert charger output specs from Ah to mAh for compatibility checks.
Translate industrial battery datasheets from Ah to the mAh unit common in consumer electronics.
Quickly cross-reference battery capacity between different product listings.

Frequently Asked Questions

Last updated: 2026-07-01 · Reviewed by Nham Vu